The present invention relates to a technique of managing a plurality of data storage apparatuses in a computer system including a plurality of data storage apparatuses, and in particular to a technique of managing data storage apparatuses in a computer system in which those data storage apparatuses are connected hierarchically.
A storage area network, i.e., a network for data storage apparatuses, in which a plurality of data storage apparatuses and a plurality of computers are connected through devices such as switches and hubs, is becoming popular. In a storage area network, a network of fibre channels is mainly used as a network connecting data source apparatuses and computers, and a computer and a data storage apparatus send and receive SCSI (Small Computer System Interface) command blocks on a fibre channel, to send and receive data and programs used by the computer or data generated by the computer.
On the other hand, management of a configuration of data storage apparatuses and computers and monitoring of occurrence of a failure are performed by sending and receiving SNMP (Simple Network Management Protocol) or CIM/WBEM (Common Information Model/Web-Based Enterprise Management) through IP network constructed separately from the above network of the fibre channels. This network is called a management network.
Thus, management and operation of a computer system comprising a plurality of data storage apparatuses, a plurality of computers and a plurality of switches and hubs are performed by constructing two networks, i.e., a storage area network and a management network (See, for example, Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-288055).
On the other hand, there is a system in which a first data storage apparatus and a second data storage apparatus are hierarchically connected to a computer (See, fur example, Patent Document 2: Published Japanese Translation No. 10-508967 of International Application). Patent Document 2 discloses a storage system that realizes online data migration between the hierarchically-connected first data storage apparatus and the second data storage apparatus while the computer is not aware of the hierarchy of the data storage apparatuses.
In a computer system having a plurality of hierarchically-connected data storage apparatuses, it is not necessary for the computer to be aware of the hierarchy of the data storage apparatuses, when data storage apparatuses is sending/receiving the data to/from the computer, as disclosed in Patent Document 2.
However, in the case of performing operation such as deletion of a storage area provided by a data storage apparatus to the computer, an administrator should be aware of the configuration of the data storage apparatuses. This is because, for example, when the administrator deletes a storage area of a lower data storage apparatus without considering the hierarchy, a storage area used by an upper data storage apparatus is deleted also. When the administrator performs incorrect operation on a storage area without considering the hierarchy or the data storage apparatuses, it is possible to lose data held in the storage area. Thus, in a computer system including data storage apparatuses, it is unavoidable to employ a technique of preventing such incorrect operation.